package j04hashmap;
import java.util.HashMap;
import java.util.Hashtable;
import java.util.Map;
import java.util.TreeMap;

public class J4tree {
    public static void main(String[] args) {
        Map<String,Integer> m1 = new TreeMap<>((s1,s2)->s2.compareTo(s1));
        m1.put("x",4);
        m1.put("a",4);
        m1.put("m",4);
        m1.put("c",4);
        System.out.println("m1 = " + m1);
        System.out.println("========");
        Map<String,Integer> table1 = new Hashtable<>();
        Map<String,Integer> table2 = new HashMap<>();
        table1.put(null,3);
        System.out.println("table1 = " + table1);
    }
}
